1. Field of the Invention
The present invention relates to a composition intended for decontamination of materials soiled by toxic agents, particularly a peracid-based composition for effective decontamination of materials soiled by toxic agents such as organophosphorous and organosulfur compounds without significantly degrading said materials.
2. Description of Related Art
It is known that various cholinesterase-inhibiting organophosphorous compounds such as organophosphorous, amidophosphates, organoamidophosphates, thiolophosphates, thiolophosphonates, and amidothiolophosphates can be used in agriculture as insecticides and pesticides. On the other hand, certain organosulfur compounds are known as vesicants and used as chemical warfare agents.
Of the best-known organophosphorous compounds used as pesticides or insecticides in agriculture, O,O-diethyl O-p-nitrophenyl phosphate (Paraoxon) and O,O-diethyl O-p-nitrophenyl thiophosphate (Parathion) may be cited, while O-ethyl S-(2-diisopropylaminoethyl)methyl thiolophosphonate (VX) is a well-known chemical warfare agent. These compounds act by irreversibly blocking nerve transmission by forming covalent bonds with acetylcholinesterase, causing death by buildup of acetylcholine in the organism. Another organosulfur compound used as a chemical warfare agent is 2,2'-dichlorodiethyl sulfide (yperite).
If such compounds are used intentionally or accidentally, self-protection is important and it is particularly important to decontaminate the materials with which they have come in contact rapidly and effectively. Hence it is useful to have reagents or compositions able almost instantly to destroy such organophosphorous and organosulfur compounds.
One of the difficulties encountered in practice has to do with the need to avoid degrading the materials to be decontaminated as far as possible. Thus, the most effective compositions currently used in decontamination technology are sodium hydroxide solutions in methyl glycol with diethylamine, or calcium hypochlorite, but these solutions are highly corrosive.
A number of studies have shown that nucleophilic compounds have the properties required for eliminating toxins in the organophosphorous and organosulfur series. C. A. Bunton et al., J. Am. Chem. Soc., 95, 2912 (1973) have shown the properties of the hydroxyl ions for this purpose; other reagents have also been proposed including hydroxamic acids, oximes, mono- and polyphenols, aldehyde hydrates, certain amines, and calcium or sodium hypochlorites.
It has also been proposed that peroxyanions such as anions of hydrogen peroxide, tert-butyl hydroperoxide, perborates, and peracids be used due to their simultaneously nucleophilic and oxidizing properties.
These compounds can be used in compositions also containing surfactants improving contact between the reagent used and the toxin to be eliminated in order to speed up decontamination. In particular, the use of surfactants of the quaternary ammonium type speeds up destruction of toxins by micellar catalysis.
Thus, French patent A-2,651,133 describes compositions made up of solutions containing linear long-carbon-chain peracids with pH values between 6 and 8, generally associated with surfactants such as cetyltrimethylammonium bromide, cetyldimethyl-2-hydroxyethylammonium bromide, cetylmethylbis(2-hydroxyethyl)ammonium bromide, or cetyl-1,4-diazabicyclo(2,2,2)octylammonium bromide. Such compositions destroy Paraoxon, VX, and yperite. However, the peracids used are not commercially available and the stability of the compositions is unsatisfactory.
French patent A-2,676,368 describes aqueous compositions based on magnesium monoperoxyphthalate and a surfactant of the quaternary ammonium salt type useable for decontaminating materials soiled by certain neurotoxic agents such as VX, and vesicants such as yperite.
Destruction of yperite and allied compounds by oxidizers, particularly by potassium monopersulfate, has been described by C. Lion et al., Phosphorus, Sulfur, and Silicon, 79, 141-145 (1993), who have shown that the reaction is specific to organosulfur compounds.
Hence, there remains the need to have available compositions capable of effectively and rapidly destroying the aforementioned toxic organophosphorous and organosulfur compounds in order to decontaminate materials soiled by these compounds without degrading them.